Frozen & Strict Output

Prevent accidental mutations and catch typos at runtime.

Usage

import { createEnv } from "@frauschert/env-guard";

const env = createEnv(
  {
    PORT: { type: "number", required: true },
    HOST: { type: "string", default: "localhost" },
  },
  { freeze: true, strict: true },
);

// freeze: property assignments throw in strict mode
env.PORT = 9999; // ❌ TypeError: Cannot assign to read only property

// strict: accessing keys not in the schema throws
env.PROT; // ❌ Error: Attempted to access unknown env variable 'PROT'

Options

Option	Effect
freeze	Calls Object.freeze on the result — mutations throw
strict	Wraps in a Proxy — accessing any key not in the schema throws

Combining Options

• freeze and strict can be used independently or together.
• strict works with watch — refresh(), on(), and off() remain accessible.
• freeze deep-freezes nested group sub-objects.

WARNING

freeze cannot be combined with watch (refresh needs to mutate the object). Attempting both throws at creation time. This is enforced at the type level and at runtime.